Organopolysiloxane compositions which can be crosslinked at room temperature to form elastomers have been used heretofore for sealing joints in facade and window construction, in the sanitary field and in industry. However, the use of compositions of this type is limited, if it is necessary, to paint the organopolysiloxane elastomers themselves or the adjacent components since it is very difficult to overcoat organopolysiloxane elastomers.
Heretofore, paintability of organopolysiloxane elastomers have been achieved by applying certain silanes to the crosslinked organopolysiloxanes before overcoating the crosslinked polysiloxanes with paint or by mixing these silanes with the paint just prior to application (German Patent No. 2,852,000) or providing the organopolysiloxane with certain additives before crosslinking (cf., for example, European Patent No. 96,424) or employing dyes containing organosiloxane units as paints (cf., for example, U.S. Pat. No. 4,038,293).
Compared to the previously known solutions to improving the paintability of organopolysiloxane elastomers or providing a means to overcoat organopolysiloxane elastomers, the compositions of this invention have the advantage that it is possible to render a relatively large number of types of crosslinked organopolysiloxanes paintable, i.e., the paintability of the organopolysiloxanes is not limited to a specific crosslinked system. In addition, the crosslinked organopolysiloxanes can be coated directly with a paint, i.e., no additional additives or process steps are necessary, which makes it simple to overcoat the elastomers, and the crosslinked organopolysiloxanes can be overcoated with a relatively large number of types of paints, i.e., it is not necessary to use special-purpose and relatively expensive paints, but instead commercially available paints can be used.
Therefore, it is an object of the present invention to improve the paintability of organopolysiloxane elastomers. Another object of the present invention is to provide a method for overcoating organopolysiloxane elastomers.